I have asthma and allergies and have been having an extremely hard time with both as of late. This air purifier is quiet, and works very efficiently. I started to notice a difference after the second day of having it. Now after a few weeks, I continue to see improvement. At home, my allergies are so much better. I am having fewer episodes with my asthma and feeling so much better. I live in a two bedroom apartment that is pretty open. The purifier does well for the whole space. I am thinking of getting a second one for the bedroom that I sleep in.